1. Field of the Invention
This invention relates to agent dispensers of the fluid imbibing type such as those which are driven osmotically and, more particularly, to an agent dispenser having a catheter which can be preprimed to facilitate the application of a drug or other fluid to a body part.
Fluid imbibing osmotic agent dispensers or pumps are described in U.S. Pat. Nos. 3,760,984; 3,987,790; 3,995,631; 4,034,756; 4,474,575 and 4,539,004; all of which are incorporated herein by reference. The type of agent dispenser set forth in these disclosures includes an inner agent receiving means such as a flexible bag that holds a flowable agent to be dispensed, an intermediate fluid imbibing means such as a layer of osmotically effective solute composition, for example an inorganic salt surrounding the bag, and an outer casing having a portion that is permeable to fluid such as water and surrounds both the bag and the layer of solute composition. The bag has a discharge port which allows the agent to be directed to a location of use.
Actuation of the agent dispenser of the type described is achieved by filling the bag with a flowable agent to be dispensed, then placing the dispenser in an environment, such as in a body cavity or on the skin of a patient. Fluid, typically water is imbibed from the environment by the solute composition through the membrane and into the space between the inner bag and the membrane. The imbibed fluid squeezes the bag, thereby collapsing it and displacing the agent out of the bag through the discharge port provided therefor.
A catheter is often used with an agent dispenser of the type described. To use such a catheter requires that a relatively large number of steps be performed to place the agent dispenser in readiness for applying an agent to the human or animal body. Such steps include attaching the catheter to the filled dispenser, filling the catheter, inserting a flow moderator in the dispenser, removing a flow or moderator cap, and connecting one end of the filled catheter to the dispenser and the other end to the point of use. All of the foregoing steps require time and effort, and it is desirable to minimize the time and effort, if at all possible. Thus, a need exists for improvements in the use of an agent dispenser having a catheter and the present invention which fulfills this need.
2. DEFINITION OF TERMS
The expression "agent" as used herein denotes any drug or agent administered to produce a nutritional, therapeutic or other desired effect including for example: composition in any way affecting any biological entity; substance having a nutrient or stimulating action, or growth inhibiting, destroying or any regulating action on plant growth, controlled or otherwise; substance to be assimilated by any organism, e.g., human being, animal, or lower order organism, for its nourishment or for regulating its growth; substance exhibiting any of the above activities to be directly applied to the habitat, surroundings or environment of any of the above organisms; and substance having any other effect on any other environment, especially any aqueous environment.
Therefore, suitable agents for use with the dispenser of this invention include, without limitation, those which are generally capable of:
1. Preventing, alleviating, treating or curing abnormal or pathological conditions of the living body by such means as destroying a parasitic organism or limiting the effect of the disease of abnormality by chemically altering the physiology of the host or parasite.
2. Maintaining, increasing, decreasing, limiting or destroying a physiologic body or plant function, e.g., vitamin compositions, sex sterilants, fertility inhibitors, fertility promotors, growth promotors, and the like;
3. Diagnosing a physiological condition or state;
4. Controlling or protecting an environment or living body by attracting, disabling, inhibiting, killing, modifying, repelling or retarding an animal or microorganism, such as food and non-food baits, attractants and lures, biocides, pesticides, algicides, parasiticides, rodenticides, insecticides, fungicides, and the like;
5. Preserving, disinfecting or sterilizing; and
6. Controlling or affecting generically an environment, as by introducing a catalyst or metering a reactant into a reacting chemical system, or by effecting any chemical process therein, such as a fermentation, including propagation and/or attenuation of a microorganism.
The term "environment" as used herein denotes any prospective situs for the dispenser of this invention, or at least for the external fluid permeable membrane component thereof, which is comprised of or will provide sufficient fluid, e.g. water, for absorption into the dispenser to develop the needed osmotic pressure on which its motive force depends; and implicit in the foregoing definition of "agent" - one that will develop its action in the presence of such an environment, or one that will develop its action on a remote and/or another environment, which need not be fluid or aqueous.